Mushrooms that are not specified for recipes, but may be used as "any mushroom" are available at grocery stores - white caps, porcinis, and maybe truffles.
If you want a steady supply of alchemy ingredients, you might want to take up gardening. Your Sim will receive some seeds upon learning the gardening skill, and I usually find some alchemy ingredient seeds in the lot. You will also receive some alchemy ingredients when you learn the alchemy skill, and can either use them as is or plant them and grow some more.
I was not able to find glow orbs spawning in Sunset Valley - but I read somewhere that they only spawn during a full moon, and I had turned off moon cycles. I did eventually find some at the elixir consignment shop, and planted them to grow more.